Question 1

What is the stereochemistry of the following?  &#10;A) E&#10;B) Z&#10;C) R&#10;D) S

Accepted Answer

Stereochemistry of the double bond is determined by locating the largest substituent on each carbon of the double bond. If the largest groups of each carbon are coming off in the same direction, it is Z. If the largest groups of each carbon are coming off in different directions, it is E. R and S are only for single bonded carbons in general.

Question 2

What is the stereochemistry of the following?  &#10;A) E&#10;B) Z&#10;C) R&#10;D) S

Accepted Answer

Stereochemistry of the double bond is determined by locating the largest substituent on each carbon of the double bond. If the largest groups of each carbon are coming off in the same direction, it is Z. If the largest groups of each carbon are coming off in different directions, it is E. R and S are only for single bonded carbons in general.

Question 3

What is the correct order of stability (most stable to least stable) for alkenes?&#10;A) Tetrasubstituted > cis-disubstituted > trans-disubstituted > monosubstituted&#10;B) Trisubstituted > terminal disubstituted > trans-disubstituted > monosubstituted&#10;C) Tetrasubstituted > trans-disubstituted > cis-disubstituted > trisubstituted&#10;D) Monosubstituted > cis-disubstituted > trans-disubstituted > trisubstituted

Accepted Answer

Trisubstituted > terminal disubstituted > trans-disubstituted > monosubstituted&#10;

Question 4

What is the major product of the following reaction?  &#10;A) I&#10;B) II&#10;C) III&#10;D) IV

Accepted Answer

This reaction gives an elimination product that follows Zaitsev's rule.

Question 5

What is the major product of the following reaction?  &#10;A) I&#10;B) II&#10;C) III&#10;D) IV

Accepted Answer

This reaction gives an elimination product that follows Hofmann's rule.

Question 6

What is the major product of the following reaction?  &#10;A) I&#10;B) II&#10;C) III&#10;D) IV

Accepted Answer

In a cyclic structure the anti coplanar structure needed for elimination occurs when both the leaving group and the b hydrogen are axial. The major product arises from the elimination of the only b hydrogen that is trans to the leaving group. As a quick shortcut, if your leaving group is wedged it will need a dashed hydrogen for the anti coplanar elimination. Likewise, if your leaving group is dashed it will need a wedged hydrogen for anti coplanar elimination.

Question 7

What is the major product of the following reaction?  &#10;A) I&#10;B) II&#10;C) III&#10;D) IV

Accepted Answer

In a cyclic structure the anti coplanar structure needed for elimination occurs when both the leaving group and the b hydrogen are axial. In this structure there are multiple hydrogens that can eliminate in the anti coplanar model. The major product arises from the elimination of the only b hydrogen that is trans to the leaving group and gives the Zaitsev product. As a quick shortcut, if your leaving group is wedged it will need a dashed hydrogen for the anti coplanar elimination. Likewise, if your leaving group is dashed it will need a wedged hydrogen for anti coplanar elimination.

Question 8

What is the major product of the following reaction?  &#10;A) I&#10;B) II&#10;C) III&#10;D) IV

Accepted Answer

In a cyclic structure the anti coplanar structure needed for elimination occurs when both the leaving group and the b hydrogen are axial. In this structure there is only one hydrogen that can eliminate in the anti coplanar model. The major product arises from the elimination of the only b hydrogen that is trans to the leaving group; however this gives the Hofmann product. In cyclic structures often a Hofmann product will form as the major product instead of the Zaitsev product due to the necessity for the anti coplanar transition state.

Question 9

What is the reagent needed for the following reaction?  &#10;A) concentrated sulfuric acid and high heat&#10;B) 85 % phosphoric acid and high heat&#10;C) dilute sulfuric acid and heat&#10;D) a and b&#10;E) a, b and c

Accepted Answer

Secondary alcohols can be dehydrated using phosphoric acid and heat. They will also dehydrate with the conditions for primary alcohols, concentrated acid, and heat.

Question 10

What is the reagent needed for the following reaction?  &#10;A) concentrated sulfuric acid and high heat&#10;B) 85 % phosphoric acid and high heat&#10;C) dilute sulfuric acid and heat &#10;D) a and b&#10;E) a, b and c

Accepted Answer

Primary alcohols can only be dehydrated using concentrated acid and high heat.

Question 11

What is the major product of the following reaction?  &#10;A) I&#10;B) II&#10;C) III&#10;D) IV

Accepted Answer

The answer of What is the major product of the...

Question 12

What is the product of the following reaction?  &#10;A) I&#10;B) II&#10;C) III&#10;D) IV

Accepted Answer

The answer of What is the product of the following...

Question 13

What is the correct order of reagents needed for the following reaction? A) 1) 3 eq. NaNH₂ 2) PCl₅ 3) Butyl chloride B) 1) PCl₅ 2) 3 eq. NaNH₂ 3) Butyl chloride C) 1) PCl₅ 2) Butyl chloride 3) 3 eq. NaNH₂ D) 1) 3 eq. NaNH₂ 2) Butyl chloride 3) PCl₅

Accepted Answer

The answer of What is the correct order of reagents...

Question 14

What is the correct order of reagents needed for the following reaction? A) 1) 3 eq. NaNH₂ 2) Butyl Chloride 3) H₂/Lindlar's Catalyst B) 1) 3 eq. NaNH₂ 2) Butyl Chloride 3) Li in NH₃ 4) NH₄Cl C) 1) 3 eq. NaNH₂ 2) Butyl Chloride 3) H₂/Pt D) 1) 3 eq. NaNH₂ 2) Propyl Chloride 3) Li in NH₃ 4) NH₄Cl

Accepted Answer

The answer of What is the correct order of reagents...

Question 15

What reagent is needed for the following reaction? A) H₂/Lindlar's Catalyst B) 1) Li in NH₃ 2) NH₄Cl C) H₂/Pt D) H₂/Ni₂B E) a and d F) none of the above

Accepted Answer

The answer of What reagent is needed for the following...

Question 16

What reagent is needed for the following reaction? A) H₂/Lindlar's Catalyst B) 1) Li in NH₃ 2) NH₄Cl C) H₂/Pt D) H₂/Ni₂B E) a and d F) none of the above

Accepted Answer

The answer of What reagent is needed for the following...

Deck 7: Alkenes and Alkynes I